Method and device for controlling a multi-split air conditioner, and multi-split air conditioner

Abstract

The application relates to the control technology field of multi-connected air conditioners, and discloses a method for controlling a multi-connected air conditioner, which comprises the following steps: obtaining a high-pressure side pressure value and a low-pressure side pressure value of a compressor of the multi-connected air conditioner; determining a target frequency-increasing strategy of the compressor under the condition that the high-pressure side pressure value, the low-pressure side pressure value and the current time meet an early oil return condition; and controlling the multi-connected air conditioner to execute the target frequency-increasing strategy. In this way, a more accurate target frequency-increasing strategy can be determined under the condition that the high-pressure side pressure value, the low-pressure side pressure value and the current time meet the early oil return condition, so that the multi-connected air conditioner is controlled to execute the target frequency-increasing strategy, and oil return control is performed on the multi-connected air conditioner in advance, so that the frequency-increasing operation in this way does not cause the pressure on the low-pressure side of the compressor to be excessively low, and the situation that the multi-connected air conditioner enters the anti-freezing mode in advance due to the early frosting of indoor units is avoided. The application further discloses a device for controlling a multi-connected air conditioner and a multi-connected air conditioner.

Description

Technical Field

[0001] This application relates to the field of multi-split air conditioning control technology, for example to a method, apparatus and multi-split air conditioning for controlling a multi-split air conditioner. Background Technology

[0002] Currently, multi-split air conditioners operate at low compressor frequencies under low-temperature, low-load cooling conditions, resulting in low refrigerant flow rates in the refrigerant lines. This prevents the return of accumulated lubricating oil from the indoor unit to the compressor. Therefore, oil return control is necessary to ensure reliable compressor operation with sufficient oil. Specifically, multi-split air conditioner compressors require frequency increases. This increase in compressor frequency temporarily raises the high-pressure side pressure and lowers the low-pressure side pressure. If frequency control is inadequate, excessively low pressure can occur, causing the multi-split air conditioner to prematurely enter anti-freeze mode. Therefore, more precise control of multi-split air conditioners to prevent indoor unit frosting due to excessively low compressor low-pressure side pressure is a critical technical problem that needs to be solved.

[0003] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0005] This disclosure provides a method, apparatus, and multi-split air conditioner for controlling a multi-split air conditioner, so as to more accurately control the oil return of the multi-split air conditioner in advance, so as to avoid the occurrence of indoor unit frost due to excessively low pressure on the low-pressure side of the compressor.

[0006] In some embodiments, the method for controlling a multi-split air conditioner includes: obtaining the high-pressure side pressure value and the low-pressure side pressure value of the multi-split air conditioner compressor; determining a target frequency increase strategy for the compressor when the high-pressure side pressure value, the low-pressure side pressure value, and the current time meet the conditions for early oil return; and controlling the multi-split air conditioner to execute the target frequency increase strategy.

[0007] In some embodiments, the method for controlling a multi-split air conditioner includes: extracting a high-pressure calibration value and a low-pressure calibration value that match the outdoor ambient temperature of the multi-split air conditioner from a low-temperature cooling threshold table; using the high-pressure calibration value as a first threshold; using the product of the low-pressure calibration value and a first set coefficient as a second threshold; and determining that the high-pressure side pressure value, the low-pressure side pressure value, and the current time meet the conditions for early oil return when the high-pressure side pressure value is higher than the first threshold, the low-pressure side pressure value is higher than the second threshold, and the current time is within the early oil return period.

[0008] In some embodiments, the method for controlling a multi-split air conditioner includes: dividing the compressor's frequency ramping phase into multiple frequency ramping cycles according to a preset frequency step size; sequentially determining the frequency ramping strategy for each frequency ramping cycle; determining the compressor's target frequency ramping strategy as sequentially executing the frequency ramping strategy for each frequency ramping cycle until the compressor's operating frequency rises to the target oil return frequency.

[0009] In some embodiments, the method for controlling a multi-split air conditioner includes: calculating a first rate of decrease in the low-pressure side pressure value of the compressor within a first frequency increase cycle; calculating a first duration of decrease required for the low-pressure side pressure value of the compressor to decrease to a third threshold based on the first rate of decrease; determining a second frequency increase rate for the multi-split air conditioner compressor if the first frequency increase duration required for the compressor to increase to a target oil return frequency is less than the first duration of decrease; and determining that the frequency increase strategy for the second frequency increase cycle is to control the multi-split air conditioner to increase its frequency according to the second frequency increase rate within the second frequency increase cycle.

[0010] In some embodiments, the method for controlling a multi-split air conditioner includes: calculating a first duration threshold and a second duration threshold based on a first descent duration; determining a second frequency ramp rate of the multi-split air conditioner compressor as 1 / (N-2) when the first frequency ramp duration is less than the first duration threshold; determining a second frequency ramp rate of the multi-split air conditioner compressor as 1 / (N-1) when the first frequency ramp duration is greater than the first duration threshold and less than the second duration threshold; and determining a second frequency ramp rate of the multi-split air conditioner compressor as 1 / N when the first frequency ramp duration is greater than the second duration threshold and less than the first descent duration; wherein N is the frequency ramp duration of the first frequency ramp cycle.

[0011] In some embodiments, the method for controlling a multi-split air conditioner includes: when the first frequency increase duration required for the compressor to increase to the target oil return frequency is greater than the first frequency decrease duration, controlling the multi-split air conditioner to open the pressure balancing solenoid valve and increase the opening of the electronic expansion valve of the indoor unit of the multi-split air conditioner; when the compressor operates at the current operating frequency for a preset duration, reducing the opening of the electronic expansion valve to restore it to its initial opening; and controlling the multi-split air conditioner to increase its frequency according to the first frequency increase rate during the second frequency increase cycle.

[0012] In some embodiments, the method for controlling a multi-split air conditioner includes: calculating a second rate of decrease in the low-pressure side pressure value of the compressor during a second frequency increase cycle; calculating a second duration of decrease required for the low-pressure side pressure value of the compressor to decrease to a third threshold based on the second rate of decrease; determining a third frequency increase rate for the multi-split air conditioner compressor if the second frequency increase duration required for the compressor to increase to a target oil return frequency is less than the second duration of decrease; and determining that the frequency increase strategy for the third frequency increase cycle is to control the multi-split air conditioner to increase its frequency according to the third frequency increase rate during the third frequency increase cycle.

[0013] In some embodiments, the device for controlling a multi-split air conditioner includes: an acquisition module configured to acquire the high-pressure side pressure value and the low-pressure side pressure value of the multi-split air conditioner compressor; a determination module configured to determine a target frequency increase strategy for the compressor when the high-pressure side pressure value, the low-pressure side pressure value, and the current time meet the conditions for early oil return; and a control module configured to control the multi-split air conditioner to execute the target frequency increase strategy.

[0014] In some embodiments, the apparatus for controlling a multi-split air conditioner includes a processor and a memory storing program instructions, the processor being configured to execute the aforementioned method for controlling a multi-split air conditioner when the program instructions are executed.

[0015] In some embodiments, the multi-split air conditioner includes the aforementioned device for controlling the multi-split air conditioner.

[0016] The method, apparatus, and multi-split air conditioner for controlling a multi-split air conditioner provided in this disclosure can achieve the following technical effects: by obtaining the high-pressure side pressure value and low-pressure side pressure value of the multi-split air conditioner compressor; and when the high-pressure side pressure value, low-pressure side pressure value, and current time meet the conditions for early oil return, a target frequency increase strategy for the compressor is determined; thereby controlling the multi-split air conditioner to execute the target frequency increase strategy. With this solution, a more precise target frequency increase strategy for the compressor can be determined when the high-pressure side pressure value, low-pressure side pressure value, and current time meet the conditions for early oil return. This allows for more precise control of early oil return in the multi-split air conditioner while controlling it to execute the target frequency increase strategy, ensuring that frequency increase in this way does not lead to excessively low pressure on the low-pressure side of the compressor, and also preventing the multi-split air conditioner from prematurely entering anti-freeze mode due to premature frosting of the indoor unit.

[0017] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0018] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein:

[0019] Figure 1 This is a schematic diagram of a method for controlling a multi-split air conditioner provided in an embodiment of this disclosure;

[0020] Figure 2 This is a schematic diagram of a method for determining a target upsampling strategy provided in an embodiment of this disclosure;

[0021] Figure 3 This is a schematic diagram of a method for determining a second up-frequency cycle according to an embodiment of the present disclosure;

[0022] Figure 4 This is a schematic diagram of a method for determining a boosting strategy for a third boosting cycle, provided in an embodiment of this disclosure;

[0023] Figure 5 This is a schematic diagram of a device for controlling a multi-split air conditioner provided in an embodiment of this disclosure;

[0024] Figure 6 This is a schematic diagram of another device for controlling a multi-split air conditioner provided in an embodiment of this disclosure. Detailed Implementation

[0025] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0026] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0027] Unless otherwise stated, the term "multiple" means two or more.

[0028] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0029] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0030] The term "correspondence" can refer to an association or binding relationship. The correspondence between A and B means that there is an association or binding relationship between A and B.

[0031] In this embodiment of the disclosure, smart home appliances refer to home appliances formed by introducing microprocessors, sensor technology and network communication technology into home appliances. They have the characteristics of intelligent control, intelligent sensing and intelligent application. The operation of smart home appliances often relies on the application and processing of modern technologies such as the Internet of Things, the Internet and electronic chips. For example, smart home appliances can be connected to electronic devices to enable users to remotely control and manage smart home appliances.

[0032] In this embodiment of the disclosure, the terminal device refers to an electronic device with wireless connectivity. The terminal device can communicate with the aforementioned smart home appliances by connecting to the internet, or directly via Bluetooth, Wi-Fi, or other methods. In some embodiments, the terminal device may be, for example, a mobile device, a computer, or an in-vehicle device built into a hovercraft, or any combination thereof. Mobile devices may include, for example, mobile phones, smart home devices, wearable devices, smart mobile devices, virtual reality devices, or any combination thereof. Wearable devices may include, for example, smartwatches, smart bracelets, pedometers, etc.

[0033] Figure 1 This is a schematic diagram of a method for controlling a multi-split air conditioner provided in an embodiment of this disclosure; combined with Figure 1 As shown in the embodiments of this disclosure, a method for controlling a multi-split air conditioner is provided, comprising:

[0034] S11, the multi-split air conditioner obtains the high-pressure side pressure value and low-pressure side pressure value of the multi-split air conditioner compressor.

[0035] S12, the multi-split air conditioner determines the target frequency increase strategy of the compressor when the high-pressure side pressure value, the low-pressure side pressure value, and the current time meet the conditions for early oil return.

[0036] S13, Multi-split air conditioner control: Multi-split air conditioner executes target frequency increase strategy.

[0037] In this solution, the multi-split air conditioner is connected to multiple pressure sensors located at different positions. These sensors allow the multi-split air conditioner to obtain the high-pressure and low-pressure values ​​of the compressor. This method enables accurate acquisition of both high-pressure and low-pressure values.

[0038] Furthermore, the high-pressure side pressure value, low-pressure side pressure value, and current time are determined to meet the early oil return condition by the following method: Extract the high-pressure calibration value and low-pressure calibration value that match the outdoor ambient temperature of the multi-split air conditioner from the low-temperature cooling threshold table; use the high-pressure calibration value as the first threshold; use the product of the low-pressure calibration value and a first set coefficient as the second threshold; when the high-pressure side pressure value is higher than the first threshold, the low-pressure side pressure value is higher than the second threshold, and the current time is within the early oil return period, it is determined that the high-pressure side pressure value, low-pressure side pressure value, and current time meet the early oil return condition. In this way, the target frequency increase strategy of the compressor can be determined when the high-pressure side pressure value, low-pressure side pressure value, and current time meet the early oil return condition. This method allows for precise determination of the timing of the target frequency increase strategy. Therefore, after accurately determining the target frequency increase strategy of the compressor, the multi-split air conditioner can be controlled to execute the target frequency increase strategy to achieve early oil return control of the multi-split air conditioner.

[0039] The method for controlling a multi-split air conditioner provided in this disclosure obtains the high-pressure side pressure value and the low-pressure side pressure value of the compressor. If the high-pressure side pressure value, the low-pressure side pressure value, and the current time meet the conditions for early oil return, a target frequency increase strategy for the compressor is determined. This allows the multi-split air conditioner to execute the target frequency increase strategy. This approach enables a more precise determination of the compressor's target frequency increase strategy when the high-pressure side pressure value, the low-pressure side pressure value, and the current time meet the conditions for early oil return. This allows for more accurate control of early oil return while controlling the multi-split air conditioner to execute the target frequency increase strategy. This prevents the low-pressure side pressure of the compressor from becoming too low due to premature frost formation on the indoor unit, thus avoiding premature anti-freezing activation of the multi-split air conditioner.

[0040] Optionally, the high-pressure side pressure value, low-pressure side pressure value, and the current moment that meet the conditions for early oil return can be determined by the following method:

[0041] The multi-split air conditioner extracts the high-pressure calibration value and low-pressure calibration value that match the outdoor ambient temperature of the multi-split air conditioner from the low-temperature cooling threshold table.

[0042] Multi-split air conditioners use the high-pressure calibration value as the first threshold.

[0043] Multi-split air conditioners use the product of the low-pressure calibration value and the first set coefficient as the second threshold.

[0044] If the high-pressure side pressure value is higher than the first threshold, the low-pressure side pressure value is higher than the second threshold, and the current time is within the early oil return period, then the high-pressure side pressure value, the low-pressure side pressure value, and the current time are determined to meet the early oil return conditions.

[0045] In this solution, the multi-split air conditioner can pre-store a low-temperature cooling threshold table. This table stores experimentally derived high-pressure and low-pressure calibration values ​​for different outdoor ambient temperatures. For example, if the outdoor ambient temperature is -5°C, the corresponding high-pressure calibration value is 18 bar, and the low-pressure calibration value is 5 bar. Thus, after obtaining the outdoor ambient temperature, the multi-split air conditioner can extract the corresponding high-pressure and low-pressure calibration values ​​from the low-temperature cooling threshold table. This method enables accurate determination of the high-pressure and low-pressure calibration values.

[0046] Furthermore, multi-split air conditioners can use the high-pressure calibration value as the first threshold. They can also use the product of the low-pressure calibration value and the first setting coefficient as the second threshold. Considering practical situations, the first setting coefficient is greater than 170%. For example, the first setting coefficient is 175%. In this way, the first and second thresholds can be accurately determined.

[0047] Furthermore, if the high-pressure side pressure value is higher than a first threshold, the low-pressure side pressure value is higher than a second threshold, and the current time falls within the early return oil period, it can be determined that the high-pressure side pressure value, low-pressure side pressure value, and current time meet the early return oil condition. The early return oil period is the time interval from 15 minutes before the normal return oil time to the normal return oil time. For example, if the normal return oil time is 8:15, then the early return oil period is 8:00 to 8:15. In this way, by combining the high-pressure side pressure value, low-pressure side pressure value, and current time, it is possible to accurately determine whether the early return oil condition is met.

[0048] Figure 2 This is a schematic diagram of a method for determining a target upsampling strategy provided in an embodiment of this disclosure; combined with Figure 2 As shown, optionally, in step S12, the target frequency increase strategy for the compressor is determined, including:

[0049] S21, the multi-split air conditioner divides the compressor's frequency ramp-up phase into multiple frequency ramp-up cycles according to a preset frequency step size.

[0050] S22, the multi-split air conditioner sequentially determines the frequency increase strategy for each frequency increase cycle.

[0051] S23, the multi-split air conditioner determines the target frequency increase strategy of the compressor to execute the frequency increase strategy for each frequency increase cycle in sequence until the compressor's operating frequency increases to the target oil return frequency.

[0052] In this solution, the preset frequency step size is 1Hz. Specifically, the multi-split air conditioner divides the compressor's frequency ramp-up phase into multiple ramp-up cycles according to the preset frequency step size. For example, if the compressor operates at 35Hz before oil return and the target oil return frequency is 70Hz, then the frequency ramp-up phase from 35Hz to 70Hz can be divided into 35 ramp-up cycles with a step size of 1Hz. In this way, precise division of multiple ramp-up cycles is achieved.

[0053] Furthermore, the multi-split air conditioner can sequentially determine the frequency increase strategy for each frequency increase cycle. The frequency increase strategy for each cycle can be determined by the frequency increase situation of the previous cycle. This method facilitates adjusting the frequency increase strategy for the next frequency increase cycle based on the frequency increase situation of each previous cycle. Furthermore, the multi-split air conditioner determines the target frequency increase strategy for the compressor by sequentially executing the frequency increase strategy for each cycle until the compressor's operating frequency reaches the target oil return frequency. This method allows for more precise early oil return control of the multi-split air conditioner, ensuring that frequency increase through this method does not lead to excessively low pressure on the compressor's low-pressure side.

[0054] Figure 3 This is a schematic diagram of a method for determining a boosting strategy for a second boosting cycle, provided in an embodiment of this disclosure; combined with Figure 3 As shown, optionally, the multiple upsampling cycles include a first upsampling cycle and a second upsampling cycle, and determining the upsampling strategy for the second upsampling cycle includes:

[0055] S31, the multi-split air conditioner calculates the first rate of decrease in the compressor's low-pressure side pressure value during the first frequency increase cycle.

[0056] S32, the multi-split air conditioner calculates the first descent time required for the pressure value on the low-pressure side of the compressor to drop to the third threshold based on the first descent rate.

[0057] S33, when the first frequency increase time required for the compressor to increase to the target oil return frequency is less than the first frequency decrease time, the multi-split air conditioner determines the second frequency increase rate of the multi-split air conditioner compressor.

[0058] S34, the multi-split air conditioner determines the frequency increase strategy for the second frequency increase cycle as controlling the multi-split air conditioner to increase the frequency according to the second frequency increase rate during the second frequency increase cycle.

[0059] In this scheme, it is understood that the frequency increase strategy for each frequency increase cycle can be determined by the frequency increase situation of the previous cycle. Therefore, in order to determine the frequency increase strategy for the second frequency increase cycle, the multi-split air conditioner can calculate the first rate of decrease of the compressor low-pressure side pressure value during the first frequency increase cycle. Specifically, calculating the first rate of decrease of the compressor low-pressure side pressure value during the first frequency increase cycle includes:

[0060] v1=(Ps0-Ps1) / N

[0061] Where v1 is the first rate of decrease of the compressor's low-pressure side pressure during the first frequency increase cycle, Ps1 is the compressor's low-pressure side pressure at the end of the first frequency increase cycle, Ps0 is the compressor's low-pressure side pressure at the beginning of the first frequency increase cycle, and N is the frequency increase duration of the first frequency increase cycle. In this way, the first rate of decrease can be accurately determined.

[0062] Furthermore, the multi-split air conditioner calculates, based on the first descent rate, the first descent time required for the pressure value on the low-pressure side of the compressor to drop to the third threshold, including:

[0063] t1=(Ps1-Ps′) / ν1

[0064] Where t1 is the first descent time required for the compressor's low-pressure side pressure to drop to the third threshold, Ps1 is the compressor's low-pressure side pressure at the end of the first frequency increase cycle, Ps′ is the third threshold, and v1 is the first descent rate of the compressor's low-pressure side pressure during the first frequency increase cycle. The third threshold Ps′ is the product of the extracted low-pressure calibration value and the second set coefficient. As an example, the second set coefficient is 170%. In this way, the first descent time is accurately determined.

[0065] Alternatively, the first frequency ramp-up time required for the compressor to reach the target oil return frequency can be calculated using the following method:

[0066] t1′=(f 回油 -(f 开始 +1)) / δ1

[0067] Where t1′ is the first frequency ramp-up time required for the compressor to reach the target oil return frequency, and f 回油 For the target return oil frequency, f 开始 Let δ1 be the compressor's operating frequency at the start of the first frequency ramp-up cycle, and δ1 be the compressor's initial frequency ramp-up rate. As an example, the compressor's initial frequency ramp-up rate δ1 is 1Hz / Ns. In this way, the first frequency ramp-up time required for the compressor to reach the target oil return frequency can be accurately calculated.

[0068] Furthermore, if the first frequency increase time required for the compressor to reach the target oil return frequency is less than the first frequency decrease time, and it is determined that the compressor's frequency increase rate can be adjusted, then the multi-split air conditioner determines the second frequency increase rate of the compressor. Furthermore, the multi-split air conditioner can determine that the frequency increase strategy for the second frequency increase cycle is to control the multi-split air conditioner to increase its frequency according to the second frequency increase rate within the second frequency increase cycle. In this way, the frequency increase strategy for the second frequency increase cycle can be accurately determined.

[0069] Optionally, S33, the multi-split air conditioner determines the second frequency ramp rate of the multi-split air conditioner compressor, including:

[0070] The multi-split air conditioner calculates a first duration threshold and a second duration threshold based on the first descent duration.

[0071] If the first frequency increase duration is less than the first duration threshold, the multi-split air conditioner determines that the second frequency increase rate of the multi-split air conditioner compressor is 1 / (N-2).

[0072] When the first frequency increase duration is greater than the first duration threshold and less than the second duration threshold, the multi-split air conditioner determines that the second frequency increase rate of the multi-split air conditioner compressor is 1 / (N-1).

[0073] When the first frequency increase duration is greater than the second duration threshold and less than the first frequency decrease duration, the multi-split air conditioner determines that the second frequency increase rate of the multi-split air conditioner compressor is 1 / N.

[0074] Where N is the frequency rise time of the first frequency rise cycle.

[0075] In this solution, the multi-split air conditioner calculates a first duration threshold and a second duration threshold based on the first descent duration. Specifically, the first duration threshold = first descent duration * 40%, and the second duration threshold = first descent duration * 70%. Thus, if the first frequency increase duration is less than the first descent duration * 40%, the multi-split air conditioner determines the second frequency increase rate δ2 of the compressor to be 1Hz / (N-2)s; if the first frequency increase duration is greater than the first descent duration * 40% and less than the first descent duration * 70%, the multi-split air conditioner determines the second frequency increase rate δ2 of the compressor to be 1Hz / (N-1)s; and if the first frequency increase duration is greater than the first descent duration * 70% and less than the first descent duration, the multi-split air conditioner determines the second frequency increase rate δ2 of the compressor to be 1Hz / Ns. In this way, by combining the comparison results of the first descent time and the first frequency rise time, the second frequency rise rate δ2 of the multi-split air conditioner compressor in the second frequency rise cycle can be accurately determined, so that the second frequency rise rate determined by this method is more consistent with the increase of compressor frequency and the decrease of low-pressure side pressure.

[0076] Optionally, if the first frequency increase time required for the compressor to increase to the target oil return frequency is greater than the first frequency decrease time, the multi-split air conditioner controls the multi-split air conditioner to open the pressure balancing solenoid valve and increase the opening of the electronic expansion valve of the multi-split air conditioner indoor unit.

[0077] When the multi-split air conditioner operates at the current compressor operating frequency for a preset duration, it reduces the opening of the electronic expansion valve to restore it to its initial opening.

[0078] The multi-split air conditioner control system increases the frequency of the multi-split air conditioner according to the first frequency increase rate during the second frequency increase cycle.

[0079] In this scheme, if the first frequency increase time required for the compressor to reach the target oil return frequency is greater than the first frequency decrease time, the multi-split air conditioner controls the multi-split air conditioner to open the pressure balancing solenoid valve and increase the opening of the electronic expansion valve of the indoor unit. Specifically, controlling the multi-split air conditioner to open the pressure balancing solenoid valve and increase the opening of the electronic expansion valve of the indoor unit includes: the multi-split air conditioner opening the pressure balancing solenoid valve and increasing the opening of the electronic expansion valve of the indoor unit by 10%. Further, after operating at the current compressor operating frequency for a preset time, the multi-split air conditioner reduces the opening of the electronic expansion valve to restore it to its initial opening. The preset time can be 2Ns, where N is the frequency increase time of the first frequency increase cycle. The initial opening is the opening value of the electronic expansion valve before adjustment. Further, the multi-split air conditioner controls the multi-split air conditioner to increase the frequency according to the first frequency increase rate during the second frequency increase cycle. With this scheme, the control scheme of the multi-split air conditioner can be accurately determined when the first frequency increase time required for the compressor to increase to the target oil return frequency is longer than the first frequency decrease time. This allows for more precise compressor frequency increase during the second frequency increase cycle, thereby achieving low-pressure protection control.

[0080] Optionally, to accurately determine the closing timing of the pressure balancing solenoid valve, the low-pressure side pressure value of the compressor can be obtained, and the multi-split air conditioner can be controlled to close the pressure balancing solenoid valve when the low-pressure side pressure value reaches a fourth threshold. Here, the fourth threshold is equal to the third threshold multiplied by 120%. This allows for a more precise determination of the closing timing of the pressure balancing solenoid valve.

[0081] Figure 4 This is a schematic diagram of a method for determining a boosting strategy for a third boosting cycle, provided in an embodiment of this disclosure; combined with Figure 4 As shown, optionally, the multiple upsampling cycles include a first upsampling cycle, a second upsampling cycle, and a third upsampling cycle. Determining the upsampling strategy for the third upsampling cycle includes:

[0082] S41, the multi-split air conditioner calculates the second rate of decrease of the compressor low-pressure side pressure value during the second frequency increase cycle.

[0083] S42, the multi-split air conditioner calculates the second descent time required for the pressure value on the low-pressure side of the compressor to drop to the third threshold based on the second descent rate.

[0084] S43, if the second frequency increase time required for the compressor to increase to the target oil return frequency is less than the second frequency decrease time, the multi-split air conditioner determines the third frequency increase rate of the multi-split air conditioner compressor.

[0085] S44, the multi-split air conditioner determines the frequency increase strategy for the third frequency increase cycle as controlling the multi-split air conditioner to increase the frequency according to the third frequency increase rate within the third frequency increase cycle.

[0086] In this scheme, it is understood that the frequency increase strategy for each frequency increase cycle can be determined by the frequency increase situation of the previous cycle. Therefore, in order to determine the frequency increase strategy for the third frequency increase cycle, the multi-split air conditioner can calculate the second rate of decrease of the compressor low-pressure side pressure value during the second frequency increase cycle. Specifically, calculating the second rate of decrease of the compressor low-pressure side pressure value during the second frequency increase cycle includes:

[0087] V2=(Ps1-Ps2) / N

[0088] Where v2 is the second rate of decrease of the compressor's low-pressure side pressure during the second frequency increase cycle, Ps2 is the compressor's low-pressure side pressure at the end of the second frequency increase cycle, Ps1 is the compressor's low-pressure side pressure at the beginning of the second frequency increase cycle, and N is the frequency increase duration of the second frequency increase cycle. In this way, the second rate of decrease can be accurately determined.

[0089] Furthermore, the multi-split air conditioner calculates, based on the second descent rate, the first descent time required for the pressure value on the low-pressure side of the compressor to drop to the third threshold, including:

[0090] T2=(Ps2-Ps′) / ν2

[0091] Where T2 is the second descent time required for the compressor's low-pressure side pressure to drop to the third threshold, Ps2 is the compressor's low-pressure side pressure at the end of the second frequency ramp-up cycle, Ps′ is the third threshold, and v2 is the second descent rate of the compressor's low-pressure side pressure during the second frequency ramp-up cycle. The third threshold Ps′ is the product of the extracted low-pressure calibration value and the second setting coefficient. As an example, the second setting coefficient is 170%. In this way, the second descent time is accurately determined.

[0092] Alternatively, the second frequency ramp-up time required for the compressor to reach the target oil return frequency can be calculated in the following way:

[0093] T2′=(f 回油 -(f 开始 +2)) / δ2

[0094] Where t2′ is the second frequency ramp-up time required for the compressor to reach the target oil return frequency, and f 回油 For the target return oil frequency, f 开始 δ1 represents the compressor's operating frequency at the start of the first frequency ramp-up cycle, and δ2 represents the compressor's frequency ramp-up rate in the second frequency ramp-up cycle. Using this method, the second frequency ramp-up time required for the compressor to reach the target oil return frequency can be accurately calculated.

[0095] Furthermore, if the second frequency ramp-up time required for the compressor to reach the target oil return frequency is less than the second frequency descent time, and it is determined that the compressor's frequency ramp-up rate can be adjusted, then the multi-split air conditioner determines its third frequency ramp-up rate. The method for determining the third frequency ramp-up rate can refer to the method for determining the second frequency ramp-up rate. This will not be elaborated upon further.

[0096] In this way, the multi-split air conditioner can determine the frequency increase strategy for the third frequency increase cycle as controlling the multi-split air conditioner to increase the frequency according to the third frequency increase rate within the third frequency increase cycle. In this way, the frequency increase strategy for the third frequency increase cycle can be accurately determined.

[0097] In this scheme, the frequency increase cycle is divided into increments of 1 Hz. The frequency increase rate of each cycle is determined by calculation and analysis of the data obtained from the previous cycle. This ensures that the low pressure on the compressor's low-pressure side does not drop too quickly. The frequency increase rate of each cycle is corrected based on the rate of decrease in the low pressure value on the low-pressure side. This ensures that the frequency increases to the oil return frequency in the shortest possible time to initiate oil return control without affecting the significant decrease in pressure (Ps), resulting in excellent performance.

[0098] In other words, the up-rate of the nth up-rate cycle can be calculated as follows:

[0099] The multi-split air conditioner calculates the (n-1)th rate of decrease in the compressor's low-pressure side pressure value during the (n-1)th cycle.

[0100] The multi-split air conditioner calculates the (n-1)th descent time required for the pressure value on the low-pressure side of the compressor to drop to the third threshold based on the (n-1)th descent rate.

[0101] If the (n-1)th frequency increase time required for the compressor to increase to the target oil return frequency is less than the (n-1)th frequency decrease time, the multi-split air conditioner determines the nth frequency increase rate of the multi-split air conditioner compressor.

[0102] The frequency increase strategy for determining the nth frequency increase cycle of a multi-split air conditioner is to control the multi-split air conditioner to increase the frequency according to the nth frequency increase rate within the nth frequency increase cycle.

[0103] In this embodiment, the (n-1)th descent rate, the (n-1)th descent duration, and the (n-1)th frequency increase duration can be calculated respectively as described above. The nth frequency increase rate is determined by combining the comparison results of the (n-1)th descent duration and the (n-1)th frequency increase duration. Therefore, the frequency increase strategy for the multi-split air conditioner in the nth frequency increase cycle is to control the multi-split air conditioner to increase its frequency according to the nth frequency increase rate within the nth frequency increase cycle. In this way, the frequency increase rate of the nth frequency increase cycle can be accurately determined.

[0104] Figure 5 This is a schematic diagram of a device for controlling a multi-split air conditioner provided in an embodiment of this disclosure; combined with Figure 5 As shown, this embodiment of the present disclosure provides an apparatus for controlling a multi-split air conditioner, including an acquisition module 51, a determination module 52, and a control module 53. The acquisition module 51 is configured to acquire the high-pressure side pressure value and the low-pressure side pressure value of the multi-split air conditioner compressor; the determination module 52 is configured to determine the target frequency increase strategy of the compressor when the high-pressure side pressure value, the low-pressure side pressure value, and the current time meet the conditions for early oil return; the control module 53 is configured to control the multi-split air conditioner to execute the target frequency increase strategy.

[0105] The apparatus for controlling a multi-split air conditioner provided in this disclosure obtains the high-pressure side pressure value and the low-pressure side pressure value of the multi-split air conditioner compressor; and determines the target frequency increase strategy of the compressor when the high-pressure side pressure value, the low-pressure side pressure value, and the current time meet the conditions for early oil return; thereby controlling the multi-split air conditioner to execute the target frequency increase strategy. This scheme enables a more precise determination of the compressor's target frequency increase strategy when the high-pressure side pressure value, the low-pressure side pressure value, and the current time meet the conditions for early oil return. This allows for more accurate control of early oil return in the multi-split air conditioner while controlling it to execute the target frequency increase strategy, ensuring that frequency increase in this way does not lead to excessively low pressure on the compressor's low-pressure side, and also avoids the multi-split air conditioner prematurely entering anti-freeze mode due to premature frosting of the indoor unit.

[0106] Figure 6 This is a schematic diagram of another device for controlling a multi-split air conditioner provided in this disclosure embodiment; combined with Figure 6 As shown, this disclosure provides an apparatus for controlling a multi-split air conditioner, including a processor 100 and a memory 101. Optionally, the apparatus may further include a communication interface 102 and a bus 103. The processor 100, communication interface 102, and memory 101 can communicate with each other via the bus 103. The communication interface 102 can be used for information transmission. The processor 100 can call logical instructions in the memory 101 to execute the method for controlling a multi-split air conditioner described in the above embodiment.

[0107] Furthermore, the logic instructions in the aforementioned memory 101 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0108] The memory 101, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of this disclosure. The processor 100 executes functional applications and data processing by running the program instructions / modules stored in the memory 101, that is, it implements the method for controlling multi-split air conditioners in the above embodiments.

[0109] The memory 101 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 101 may include high-speed random access memory and may also include non-volatile memory.

[0110] This disclosure provides a multi-split air conditioner, including the above-described device for controlling the multi-split air conditioner.

[0111] This disclosure provides a computer-readable storage medium storing computer-executable instructions configured to perform the above-described method for controlling a multi-split air conditioner.

[0112] This disclosure provides a computer program product, which includes a computer program stored on a computer-readable storage medium. The computer program includes program instructions that, when executed by a computer, cause the computer to perform the above-described method for controlling a multi-split air conditioner.

[0113] The aforementioned computer-readable storage medium may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0114] The technical solutions of this disclosure can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in this disclosure. The aforementioned storage medium can be a non-transitory storage medium, including: a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and other media capable of storing program code; it can also be a transient storage medium.

[0115] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the term "comprise" and its variations "comprises" and / or "comprising" refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0116] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0117] The methods and products (including but not limited to devices and equipment) disclosed in the embodiments herein can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units may be merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to implement this embodiment according to actual needs. In addition, the functional units in the embodiments of this disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0118] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

Claims

1. A method for controlling a multi-split air conditioner, characterized in that, include: Obtain the high-pressure side pressure value and low-pressure side pressure value of the compressor of the multi-split air conditioner; Under the condition that the high-pressure side pressure value, the low-pressure side pressure value, and the current time meet the conditions for early oil return, the target frequency increase strategy of the compressor is determined; Control the multi-split air conditioner to execute the target frequency increase strategy; Specifically, if the high-pressure side pressure value is higher than a first threshold, the low-pressure side pressure value is higher than a second threshold, and the current time is within the early oil return period, then the high-pressure side pressure value, the low-pressure side pressure value, and the current time are determined to meet the early oil return conditions.

2. The method according to claim 1, characterized in that, Extract the high-pressure calibration value and low-pressure calibration value that match the outdoor ambient temperature of the multi-split air conditioner from the low-temperature cooling threshold table. The high-pressure calibration value is used as the first threshold. The product of the low-pressure calibration value and the first set coefficient is used as the second threshold.

3. The method according to claim 1, characterized in that, Determine the target frequency increase strategy for the compressor, including: The compressor's frequency ramp-up phase is divided into multiple frequency ramp-up cycles according to a preset frequency step size; The upsampling strategy for each upsampling cycle is determined sequentially; The target frequency increase strategy for the compressor is determined to be to execute the frequency increase strategy for each frequency increase cycle sequentially until the compressor's operating frequency increases to the target oil return frequency.

4. The method according to claim 3, characterized in that, The plurality of upsampling cycles includes a first upsampling cycle and a second upsampling cycle. Determining the upsampling strategy for the second upsampling cycle includes: Calculate the first rate of decrease in the low-pressure side pressure value of the compressor during the first frequency increase cycle; Based on the first descent rate, calculate the first descent time required for the pressure value on the low-pressure side of the compressor to drop to the third threshold. If the first frequency increase time required for the compressor to increase to the target oil return frequency is less than the first frequency decrease time, the second frequency increase rate of the multi-split air conditioning compressor is determined. The frequency increase strategy for the second frequency increase cycle is to control the multi-split air conditioner to increase its frequency according to the second frequency increase rate during the second frequency increase cycle.

5. The method according to claim 4, characterized in that, Determining the second frequency ramp rate of the multi-split air conditioner compressor includes: Calculate the first duration threshold and the second duration threshold based on the first descent duration; If the first frequency increase duration is less than the first duration threshold, the second frequency increase rate of the multi-split air conditioner compressor is determined to be 1 / (N-2). If the first frequency increase duration is greater than the first duration threshold and less than the second duration threshold, the second frequency increase rate of the multi-split air conditioner compressor is determined to be 1 / (N-1). If the first frequency increase duration is greater than the second duration threshold and less than the first frequency decrease duration, the second frequency increase rate of the multi-split air conditioner compressor is determined to be 1 / N; Where N is the frequency rise time of the first frequency rise cycle.

6. The method according to claim 4, characterized in that, Also includes: If the first frequency increase time required for the compressor to increase to the target oil return frequency is greater than the first frequency decrease time, the multi-split air conditioner is controlled to open the pressure balancing solenoid valve and increase the opening of the electronic expansion valve of the indoor unit of the multi-split air conditioner. While operating at the current compressor operating frequency for a preset duration, the opening of the electronic expansion valve is reduced to restore it to its initial opening. The multi-split air conditioner is controlled to increase its frequency according to the first frequency increase rate during the second frequency increase cycle.

7. The method according to claim 3, characterized in that, The plurality of upsampling cycles includes a first upsampling cycle, a second upsampling cycle, and a third upsampling cycle. Determining the upsampling strategy for the third upsampling cycle includes: Calculate the second rate of decrease in the low-pressure side pressure value of the compressor during the second frequency increase cycle; Based on the second descent rate, calculate the second descent time required for the pressure value on the low-pressure side of the compressor to drop to the third threshold. If the second frequency increase time required for the compressor to increase to the target oil return frequency is less than the second frequency decrease time, the third frequency increase rate of the multi-split air conditioning compressor is determined. The frequency increase strategy for the third frequency increase cycle is to control the multi-split air conditioner to increase its frequency according to the third frequency increase rate within the third frequency increase cycle.

8. A device for controlling a multi-split air conditioner, characterized in that, include: The module is configured to obtain the high-pressure side pressure value and the low-pressure side pressure value of the multi-split air conditioner compressor; The determination module is configured to determine the target frequency increase strategy of the compressor when the high-pressure side pressure value, the low-pressure side pressure value, and the current time meet the conditions for early oil return. The control module is configured to control the multi-split air conditioner to execute the target up-frequency strategy; Specifically, if the high-pressure side pressure value is higher than a first threshold, the low-pressure side pressure value is higher than a second threshold, and the current time is within the early oil return period, then the high-pressure side pressure value, the low-pressure side pressure value, and the current time are determined to meet the early oil return conditions.

9. A device for controlling a multi-split air conditioner, comprising a processor and a memory storing program instructions, characterized in that, The processor is configured to, when executing the program instructions, perform the method for controlling a multi-split air conditioner as described in any one of claims 1 to 7.

10. A multi-split air conditioner, characterized in that, Includes the device for controlling a multi-split air conditioner as described in claim 8 or 9.

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